Publication Information
- Riders : Kamen Rider Den-O
- Japanese : 仮面ライダー電王
- Type : Den-O's Form
- HomeWorld : Earth (Main Timeline Continuity)
- Season : Kamen Rider Den-O
- First Appeareance : Kamen Rider Den-O Episod 1 : Here I Come!
- Main View : Full Episod
Den-O Plat Form
- Den-O Plat Form
- Rider height : 180 cm.
- Rider weight : 80 kg.
- Punching power : 1 t.
- Kicking power : 3 t.
- Maximum jump height : 10 m.
- Maximum running speed : 100 m. per 10 sec.
- Plat Form is Den-O's most basic default form undersuit, and, for a long while, Ryotaro's default form. This is because of his meek personality not generating enough willpower to give himself a proper Den-O form, until near the end, where he finally generates enough willpower to make his default form become Liner Form.
Plat Form is a black and white form that is activated when first initiating a transformation using a Rider Pass. If the corresponding color-coded button is selected, then by swiping the Pass once more, a form change will occur.
Ryotaro rarely uses this form, as it does not have sufficient armor and pales in comparison to the abilities of the other forms. Only when he does not want the assistance of the Tarōs or is transitioning into Liner Form, does he use this form. Plat Form is designed and named after a railway platform, as a reference to the fact Den-O Riders use their Platforms as a armor template. While Ryotaro is possessed by Sieg and is transforming into Wing Form, the Aura Skin becomes gold.
Single Imagin Forms
Once Ryotaro activates any of the four buttons on the Rider pass, the chosen Imagin then takes control and a transformation follows. It should be noted that these are not Ryotaro's "true" forms as these are all essentially the Imagin as riders, which they can also activate on their own supposing they have their own physical forms and are not in need of a host body.
Den-O Sword Form

- Den-O Sword Form
- Sword Form! ― Transformation announcement
- Imagin Users : Momotaros
- Height : 190 cm.
- Weight : 87kg
- Punching power : 5 t.
- Kicking power : 7 t.
- Maximum jump height : 35 m.
- Maximum running speed : 100 m. per 5.2 sec.
- Ending theme : Double-Action.
- When possessing Ryotaro (or anyone else) or by himself, Momotaros can assume Den-O's Sword through the Terminal Buckle, the first and most used form in the series. When in Sword Form he uses the DenGasher as a standard sword-style weapon. This form is the most balanced among Den-O's forms, probably due to Momotaros' prominence among the other Imagin.
Sword Form's typically used Full Charge finisher is the Extreme Slash, which is merely labeled by Momotaros as "My Finishing Move!", and famously gives it "Parts", despite said parts, those being Parts 2, 2 Dash, 3, and 5 (four was skipped because of tetraphobic reasons, even if Momo wouldn't admit it to Ryotaro) being identical to each other, in the aspect that the blade of the DenGasher detaches and flies in the path of Den-O's swings, ending with a chop that bifurcates. He also uses a "Special Version" in I'm Born! to finish off Gaoh which resembles the aforementioned parts, the only difference is that the Full Charge is used twice, with the blade striking Gaoh across the chest when it emerged from the ground.
There is also a Final Version used against the Death Imagin which uses energy from the other Taros, Sieg, and Kamen Rider Zeronos Vega Form. In the Cho Den-O series, Sword Form also has a triple Roundhouse DenRider Kick, with Momotaros dubbing this his "Super Finishing Attack". The DenKamen Mask resembles two halves of a peach, which is based on the story of Momotaro, with Momo being based off of the Oni Momotaro fought, much to Momo's constant chagrin, as Imagin are given their body's form from their host's imagination, with Ryotaro's imagination being notoriously poor.
Den-O Rod Form

- Den-O Rod Form
- Rod Form! ― Transformation announcement
- Imagin Users : Urataros
- Rider height : 187 cm.
- Rider weight : 102 kg.
- Punching power : 4.5 t.
- Kicking power : 9 t.
- Maximum jump height : 20 m.
- Maximum running speed : 100 m. per 9 sec.
- Ending theme : Double-Action Rod form
- When possessing Ryotaro (or anyone else), or by himself, Urataros can assume Rod Form. The DenGasher forms into a rod-style weapon in this form. Rod Form has the ability to fight underwater as well as extra protection. Stats-wise compared to Sword Form, it has increased kicking power, while losing some speed & punching power, and a drop in max jumping height. This is one of the more least seen forms, as Urataros rarely fights but comes through when a fight is close to water or when the other Imagin are unable to fight.
Rod Form's Full Charge finisher is also one of the two base forms that have a Rider Kick, the second being Sword Form in the Cho Den-O Series. Urataros first performs the Solid Attack, where he throws the charged DenGasher like a harpoon, which when it makes contact, it turns into a paralyzing blue hexagonal symbol, shaped like that of Urataros' own belt buckle. Once done, he attacks with the DenRider Kick to defeat the stunned opponent. The Aura Armor and DenKamen mask resembles a Sea Turtle, the animal associated with the story of Urashima Taro.

Den-O Rod Form

- Den-O Ax Form
- Ax Form! ― Transformation announcement
- Imagin Users : Kintaros
- Height : 185 cm.
- Weight : 93 kg.
- Punching power : 8 t.
- Kicking power : 5 t.
- Maximum jump height : 30 m.
- Maximum running speed : 100 m. per 7 sec.
- Ending theme : Double-Action Ax form
- When possessing Ryotaro (or anyone else), or by himself, Kintaros assumes Ax Form. In this form, the DenGasher forms an ax for short-ranged attacks. Compared to Sword Form, Ax Form gains increased punching power and defenses but loses speed and kicking power. This form is Den-O's physically strongest base form due to Kintaros' own brute strength. Kintaros tends to fight as Den-O whenever he senses crying or when hears anything similar to the Japanese word for "cry".
This form's Full Charge finisher is the Dynamic Chop, which consists of Kintaros charging the DenGasher, then chucking it skyward, jump up to catch it, then come down with a energized DenGasher backed with the momentum of the fall. Typically, Kintaros says the name of the finisher afterwards, but he has said this phrase prior to making the move once. The aura armor is golden yellow and the motif is of an axe, with a DenKamen Mask resembling the kanji for gold, all of which are elements to the story of Kintaro.

Den-O Gun Form

- Den-O Gun Form
- Gun Form! ― Transformation announcement
- Imagin Users : Ryutaros
- Height : 197 cm.
- Weight : 98 kg.
- Punching power : 6 t.
- Kicking power : 10 t.
- Maximum jump height : 42 m.
- Maximum running speed : 100 m. per 4 sec.
- Ending theme : Double-Action Gun form
- When possessing Ryotaro (or anyone else), or by himself, Ryutaros assumes Gun Form . The DenGasher forms a gun for short and long ranged attacks. Gun Form displays an increase in power, speed, and defense easily making it the most superior out of Den-O's four basic Imagin forms, though the problem with the form lies mainly with its user's mentality. Ryutaros tends to fight on a whim, as he overpowers the other Taros and Ryotaro himself, and he is the least skilled (presumably because of his age) and tends to cause more collateral damage than the other forms due to his low precision skills and the high power of the DenGasher's ammunition.
Ryutaros incorporates break dancing into his fighting style making his movement somewhat unpredictable, though this often helps with creating collateral damage in the first place, as the wild shots would only hit the surroundings of the opponents early on. This form's finisher is the Wild Shot, where a ball of energy forms in the DenGasher's muzzle, which is also fed by the energy from the orbs on Gun Form's torso armor. The Aura Armor and DenKamen resemble a dragon, the animal associated with Tatsu no ko Taro.
Den-O Wing Form

- Den-O Wing Form
- Gun Form! ― Transformation announcement
- Imagin Users : Sieg
- Height : 193cm
- Weight : 90kg
- Punching power : 4 t.
- Kicking power : 8 t.
- Maximum jump height : 50 m.
- Maximum running speed : 100 m. per 3.8 sec.
- Ending theme : Double-Action Wing form
- When possessing Ryotaro (or anyone else) or by himself, Sieg assumes Wing Form by placing the Wing Buckle over the Terminal Buckle. Unlike the other forms, Wing Form has the DenGasher become two weapons: an boomerang and a handaxe. Wing Form's suit resembles Sword Form but the Aura Skin becomes gold, different shoulder blades and thicker thigh armor are used, and the visor is blue and resembling swan wings, the bird of the ballet Swan Lake, which Sieg is based after. This form gives Den-O more mobility than Gun Form could provide via a fractionally faster running speed and a somewhat higher jumping height max, though Wing Form has lower offensive output. Wing Form's Full Charge finisher is the Royal Smash.
Climax Form
The Den-O Belt works by drawing in free energy from the surrounding area, allowing it to generate the Den-O suit, which consists of a soft but durable material called Aura Skin and tough armor called Aura Armor. As the name implies, Aura Skin and Armor are attuned to the wearer's individual aura; because of Ryotaro's weak will, he can only generate the basic Plat Form. However, possession by Imagin causes the Aura Skin and Armor to reconfigure themselves into a form that matches the Imagin's will, as well as generating a facemask called a Denkamen.
Den-O Climax Form

- Den-O Climax Form
- Den-O's sixth and second most powerful form, gained when all Tarōs but Momotaros faded away and Ryotaro's desire not to lose them created the K-Taros cell that is attached to the Den-O Belt once the code 3-6-9-# is entered. Climax Form is basically a stronger version of Sword Form that incorporates the DenKamen of the other three primary Den-O forms onto various parts of the armor.
Due to the nature of Climax Form, the Tarōs need to work as a unit to fight, and their strengths are incorporated into Climax Form. Rod Form's mask is on the right shoulder with Urataros controlling the right arm, Ax Form's mask on the left shoulder with Kintaros controlling the left arm, and Gun Form's mask on the chest with Ryutaros control the legs. Climax Form's Full Charge finishers are announced on the Belt as "Charge and Up" , allowing Den-O to perform various finishing techniques:- Boisterous Kick
- Boisterous Punch
- Boisterous Shout
- Boisterous Slash
Den-O Super Climax Form

- Den-O Super Climax Form
- Rider weight : 119 kg.
- Punching power : 8 t.
- Kicking power : 10 t.
- Maximum jump height : 50 m.
- Maximum running speed : 100 m. per 3.8 sec.
It is identical to the original Climax Form in being a stronger version of Sword Form that incorporates the DenKamen of the other three primary Den-O forms onto various parts of the armor. However, Super Climax Form also includes Wing Form's DenKamen (due to Sieg's close proximity to the formation at the time) as wings on the back of Den-O Climax and a Wing Form insignia on the mask. While not any stronger than the original Climax Form, it does gain Wing Form's greatest attributes for its agility stats, those being in running speed and jumping height.
Super Climax Form's finisher is an enhanced version of Climax Form's Boisterous Kick, where Den-O jumps into the air, then uses Wing Form's DenKamen to form giant wings to gain additional altitude, then flies towards target with a glowing foot to strike the target with.
- Main Article : Den-O Liner Form